That is the best snow I have ever seen in a SMW hack, vanilla or not. Incredible job, I'm curious how you did it!
I'll repeat what white moth said and mention the tree trunks being in the fg with the trees being in the bg looks really bizarre. I'd move those or remove the altogether.
The level itself is pretty, but it feels very flat. The grey fg dirt in particular is way too flat, I'd add a pattern if its going to take up that much of the screen. I'm assuming you were thinking of it, but it'd be cute to change the digging chuck's rock palette to be white like snow balls!